#!/usr/bin/env node

import { createHash } from "node:crypto";
import {
  cpSync,
  existsSync,
  readFileSync,
  renameSync,
  rmSync,
  writeFileSync,
} from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const assetReferencePattern =
  /(\b(?:src|href)=")(\.\/assets\/([^"?]+\.(?:css|js)))(?:\?v=[^"]+)?(")/g;

export function cacheBustZooModelingAppAssets(
  outputDir,
  { retainOriginalAssets = false } = {}
) {
  const indexPath = path.join(outputDir, "index.html");
  const source = readFileSync(indexPath, "utf8");
  const assetReferences = [...source.matchAll(assetReferencePattern)];

  if (assetReferences.length === 0) {
    const currentVersion = source.match(/\.\/assets-([a-f0-9]{12})\//)?.[1];
    if (currentVersion) {
      return { assetCount: 0, version: currentVersion };
    }
    throw new Error(`No HiCAD entry assets found in ${indexPath}`);
  }

  const assetsDir = path.join(outputDir, "assets");
  const contentHash = createHash("sha256");
  for (const reference of assetReferences.sort((a, b) =>
    a[3].localeCompare(b[3])
  )) {
    contentHash.update(reference[3]);
    contentHash.update(readFileSync(path.join(assetsDir, reference[3])));
  }

  const version = contentHash.digest("hex").slice(0, 12);
  const versionedAssetsName = `assets-${version}`;
  const versionedAssetsDir = path.join(outputDir, versionedAssetsName);
  rmSync(versionedAssetsDir, { force: true, recursive: true });
  if (retainOriginalAssets) {
    cpSync(assetsDir, versionedAssetsDir, { recursive: true });
  } else {
    renameSync(assetsDir, versionedAssetsDir);
  }

  const versionedSource = source.replace(
    assetReferencePattern,
    (_match, prefix, _assetReference, assetPath, suffix) =>
      `${prefix}./${versionedAssetsName}/${assetPath}${suffix}`
  );
  writeFileSync(indexPath, versionedSource);
  return { assetCount: assetReferences.length, version };
}

const invokedPath = process.argv[1] ? path.resolve(process.argv[1]) : "";
if (invokedPath === fileURLToPath(import.meta.url)) {
  const outputDir = path.resolve(
    process.argv.slice(2).find((argument) => !argument.startsWith("--")) ||
      "public/vendor/zoo-modeling-app"
  );
  if (!existsSync(outputDir)) {
    throw new Error(`HiCAD output directory does not exist: ${outputDir}`);
  }
  const { assetCount, version } = cacheBustZooModelingAppAssets(outputDir, {
    retainOriginalAssets: process.argv.includes("--retain-original"),
  });
  console.log(
    `Versioned ${assetCount} HiCAD entry assets as assets-${version} in ${outputDir}`
  );
}